Quoting Ram Moon, AnandX (2021-02-16 12:05:23) > Hi Chris, > > -----Original Message----- > From: dri-devel <[email protected]> On Behalf Of Chris > Wilson > Sent: Monday, February 15, 2021 6:10 PM > To: Auld, Matthew <[email protected]>; Ram Moon, AnandX > <[email protected]>; Surendrakumar Upadhyay, TejaskumarX > <[email protected]>; Ursulin, Tvrtko > <[email protected]>; Jani Nikula <[email protected]>; > [email protected]; [email protected] > Subject: Re: [Intel-gfx] [PATCH] drm/i915/gem: Add a check for object size > for corner cases > > Quoting Ram Moon, AnandX (2021-02-15 12:29:17) > > Hi Chris, > > > > -----Original Message----- > > From: dri-devel <[email protected]> On Behalf Of > > Chris Wilson > > Sent: Wednesday, February 10, 2021 4:15 PM > > To: Ram Moon, AnandX <[email protected]>; Jani Nikula > > <[email protected]>; Auld, Matthew <[email protected]>; > > Surendrakumar Upadhyay, TejaskumarX > > <[email protected]>; Ursulin, Tvrtko > > <[email protected]>; [email protected]; > > [email protected] > > Cc: Ram Moon, AnandX <[email protected]> > > Subject: Re: [Intel-gfx] [PATCH] drm/i915/gem: Add a check for object > > size for corner cases > > > > Quoting Anand Moon (2021-02-10 07:59:29) > > > Add check for object size to return appropriate error -E2BIG or > > > -EINVAL to avoid WARM_ON and successful return for some testcase. > > > > No. You miss the point of having those warnings. We need to inspect the > > code to remove the last remaining "int pagenum", and then we can remove the > > GEM_WARN_ON((sz) >> PAGE_SHIFT > INT_MAX). These are not emitted for users, > > only for us to motivate us into finally fixing the code. > > -Chris > > > > Yes, I got your point these check are meant to catch up integer overflow. > > > > I have check with the IGT testcase case _gem_create_ and > > _gem_userptr_blits_ which fails pass size *-1ull << 32* left shift > > and *0~* which leads to integer overflow ie _negative_ size passed to > > create i915_gem_create via ioctl this leads to GM_WARN_ON. > > > > Can we drop these testcase so that we don't break the kernel ? > > The kernel rejects the ioctl with the expected errno. We leave a warning > purely for the benefit of CI, only when compiled for debugging and not by > default, so that we have a persistent reminder to do the code review. > What's broken? > -Chris > > All though the testcase return with appropriate error we observe kernel taint > see below.
Which is an intentional taint added for CI so that we get a warning and a visible bug so that we can allocate resources to _fix_ the underlying problems in the code. -Chris _______________________________________________ Intel-gfx mailing list [email protected] https://lists.freedesktop.org/mailman/listinfo/intel-gfx
